JP3427725B2 - Polyester resin composition and molded product thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester resin composition capable of producing a resin molded product having excellent antistatic properties and good mechanical properties, and a molded product thereof.

[0002]

2. Description of the Related Art Thermoplastic polyesters such as polyethylene terephthalate are processed into films and containers due to their excellent physical properties (mechanical strength, moldability, storability of contents) and are widely applied as packaging materials. However, the polyester-based resin has a problem that it is easily electrostatically charged and dust or the like is easily attached to the surface of the molded product to deteriorate the appearance. In order to eliminate such obstacles due to electrification, conventionally, an antistatic agent such as a surfactant has been generally used. Antistatic agents such as surfactants exhibit an antistatic effect by utilizing the movement of charges caused by the absorption of water in the air by the hydrophilic groups in the antistatic agent. Is applied to form an antistatic layer on the surface of a polyester-based resin molded product such as a film, or is preliminarily compounded in a polyester-based resin and applied as a molded product.

However, in the method of coating on the surface of a molded article,
Since the antistatic layer on the surface is easily peeled off, the antistatic effect is poorly sustained, making it difficult to form a uniform surface coating on various molded products with complex surface shapes, and applying an antistatic agent. Therefore, there is a problem that the cost becomes high because a separate process is required.

A kneading type antistatic agent which is preliminarily blended in a polyester resin is an antistatic agent from inside the molded product even if the antistatic layer formed on the surface layer of the molded product is lost for some reason. Exudates on the surface of the molded product, and the antistatic layer can be formed again. As described above, the kneading-type antistatic agent is excellent in the durability of the antistatic effect, but has the following problems.

The antistatic agents used include ionic antistatic agents such as alkyl sulfonates and quaternary ammonium salts, and nonionic antistatic agents such as polyethers and polyhydric alcohols. The ionic antistatic agent has a relatively high antistatic effect, and although a small amount is added, it is inferior in thermal stability, so that it is prone to decomposition and coloration during processing and molding of the polyester resin. Nonionic antistatic agents of polyethers and polyhydric alcohols have relatively good compatibility with polyester and are excellent in stability, but the antistatic effect is somewhat inferior, so in order to obtain a sufficient antistatic effect. It was necessary to add a relatively large amount.

As described above, in order to obtain a sufficient antistatic effect, it is necessary to add a relatively large amount of antistatic agent, and as a result, the mechanical properties of the molded product, particularly the impact resistance, are significantly deteriorated. There was a point.

[0007]

The present invention has been made in view of the above problems, and is a thermoplastic polyester resin composition having excellent antistatic properties and mechanical properties, particularly impact resistance, and a thermoplastic polyester resin composition thereof. It is intended to provide a molded product.

[0008]

The above-mentioned problems can be solved by the following means. That is, the invention according to claim 1 is a polyfunctional compound having reactivity with a thermoplastic polyester , polyoxyalkylene glycol, and the thermoplastic polyester and the polyoxyalkylene glycol.
A polyester resin composition comprising a reactive low molecular weight compound comprising a reactive isocyanate compound .

[0009] According to a second aspect of the invention, the polyester resin composition according to claim 1, with respect to 100 parts by weight of the thermoplastic polyester, polyoxyalkylene glycol 1 to 50 parts by weight of the polyfunctional isocyanate compound 0 It is characterized by being mixed with 0.01 to 25 parts by weight.

The invention according to claim 3 is the same as claim 1 or
2. The polyester resin composition according to any one of 2 above, wherein the thermoplastic polyester is polyethylene terephthalate.

The invention according to claim 4 is the invention according to claims 1 to 3.
In the polyester resin composition according to any one of,
The thermoplastic polyester is polyethylene naphthalate.

The invention according to claim 5 is the invention as claimed in claims 1 to 3.
In the polyester resin composition according to any one of,
The thermoplastic polyester is characterized by being a biodegradable polyester comprising a polymer of oxyacid.

The invention according to claim 6 is the same as claims 1 to 3.
In the polyester resin composition according to any one of,
It is characterized in that the thermoplastic polyester is a biodegradable polyester comprising a copolymer of oxyacid.

The invention according to claim 7 is the invention according to claims 1 to 6.
A molded product obtained by molding the polyester resin composition according to any one of 1 .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The present invention is a polyester resin composition prepared by blending a polyoxyalkylene glycol and a reactive low molecular weight compound consisting of a polyfunctional isocyanate compound with respect to the thermoplastic polyester, and the thermoplastic polyester is not particularly limited. However, it is possible to use those widely known as thermoplastic polyesters composed of constitutional units derived from dicarboxylic acid and diol, but especially polyethylene terephthalate,
A biodegradable polyester made of polyethylene naphthalate or a polymer or copolymer of oxyacid is preferable.

Polyethylene terephthalate is composed of constitutional units derived from terephthalic acid and ethylene glycol. Dicarboxylic acid components other than terephthalic acid such as isophthalic acid, adipic acid and sebacic acid, diethylene glycol other than ethylene glycol, and 1,4-cyclohexanediol. It may be a copolymer containing a diol component. Similarly, a polyethylene naphthalate composed of a constituent unit derived from 2,6-naphthalenedicarboxylic acid and ethylene glycol may be a copolymer containing another constituent unit.

The biodegradable polyester made of a polymer or copolymer of oxyacid may contain a constitutional unit other than the oxyacid. Further, such a thermoplastic polyester may be blended with a small amount of another polymer, if necessary.

In the present invention, the polyoxyalkylene glycol added to the thermoplastic polyester is selected from polyglycols having terminal hydroxyl groups such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, or oxyethylene units, oxypropylene units and the like. The following polyoxyalkylene glycols can be used. The polyoxyalkylene glycol may have a hydroxyl group at the terminal and may be mainly composed of polyoxyalkylene units such as oxyethylene units and oxypropylene units.

On the other hand, polyoxyalkylene glycol
As the polyfunctional isocyanate compound to be added to the thermoplastic polyester, a compound containing two or more isocyanate groups in one molecule can be used, and an aliphatic polyisocyanate such as hexamethylene diisocyanate,
Aromatic polyisocyanates such as 4,4′-diphenylmethane diisocyanate and alicyclic polyisocyanates such as isophorone diisocyanate can be used.

The amount of polyoxyalkylene glycol added in the present invention is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the thermoplastic polyester, and if it is less than 1 part by weight, almost no antistatic effect is obtained, and 5
If it is 0 part by weight or more, the moldability and the water resistance are significantly lowered.
The amount of polyoxyalkylene glycol added is preferably 3 to 4 with respect to 100 parts by weight of the thermoplastic polyester.
0 parts by weight.

The amount of the reactive low molecular weight compound consisting of a polyfunctional isocyanate compound added to the thermoplastic polyester together with the polyoxyalkylene glycol may be 0.01 to 25 parts by weight, preferably 0.1 to 25 parts by weight. 20 parts by weight. If it is 0.01 part by weight or less, the effect of improving the physical properties is insufficient, and if it is 25 parts by weight or more, the thermal stability decreases, which is not preferable.

The thermoplastic polyester resin composition in the present invention is prepared by a suitable melt-kneading device, for example, a batch-type kneading device such as a Brabender mixer or a Banbury mixer, a continuous kneading device such as a single-screw extruder or a twin-screw extruder. It is sufficient to melt-mix a predetermined amount of a polyoxyalkylene glycol and a reactive low molecular weight compound consisting of a polyfunctional isocyanate compound into a thermoplastic polyester resin using an apparatus, and then the melt is a film using a T-die if necessary. It is also possible to form the melt blended product into pellets and use it as a material.

The thermoplastic polyester resin composition according to the present invention is similar to a general thermoplastic polyester resin,
It can be used in molding methods such as injection molding, extrusion molding, stretch blow molding, etc., and a molded article made of the resin composition can be obtained, but the molding method is not particularly limited.

<Action> In the present invention, the reaction action of the reactive low molecular weight compound consisting of the polyfunctional isocyanate compound added to the thermoplastic polyester together with the polyoxyalkylene glycol is not always clear, but it is carried out at a high temperature. Reactive functional groups such as hydroxyl groups and carboxyl groups present in polyethylene terephthalate and polyoxyalkylene glycol during melt mixing react with these reactive low molecular weight compounds to form a crosslinked structure between polyethylene terephthalate and polyoxyalkylene glycol. It is considered that the mechanical properties are improved by improving the affinity and thereby providing a finer dispersed structure.

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

[0026]

EXAMPLES < Reference Example 1> As a thermoplastic polyester resin, polyethylene terephthalate resin (manufactured by Nippon Unipet, RT543C, hereinafter P
2 parts by weight of polyethylene glycol (hereinafter abbreviated as PEG) having an average molecular weight of 4000 as polyoxyalkylene glycol and 100 parts by weight of diglycidyl hexahydrophthalate (hereinafter as abbreviated as EST epx) as a polyfunctional epoxy compound. 0.5 parts by weight was added to obtain the desired thermoplastic polyester resin composition. For the addition, a twin-screw extruder was used, and the mixture was sufficiently melt-kneaded at 265 ° C. so as to have a uniform composition, and extruded into pellets. Then, this was supplied to an in-line injection molding machine to form a test piece based on the Izod impact test method of JIS-K7110, and the impact resistance was measured. Also, using the same pellet, heat press machine to 100 mm ×
It was molded into a flat plate having a thickness of 100 mm and a thickness of 0.20 mm. The obtained flat plate was allowed to stand for 72 hours under the conditions of 25 ° C. and 65% RH, and then the surface specific resistance value was measured. The surface resistivity was measured with a micro ammeter (Takeda Riken Kogyo Co., Ltd.) and applied voltage of 5
It was measured at 00V.

<Example 1 > The same as Reference Example 1 except that 4.8 parts by weight of hexamethylene diisocyanate (hereinafter abbreviated as HMDI) was used as the polyfunctional isocyanate compound instead of the polyfunctional epoxy compound. Then, a test piece and a flat plate were obtained.

Reference Example 2 In place of the polyfunctional epoxy compound, triphenyl phosphite (hereinafter referred to as T
Abbreviated as PP) A test piece and a flat plate were obtained in the same manner as in Reference Example 1 except that 3.0 parts by weight was used.

Reference Example 3 Polyoxyalkylene glycol having an average molecular weight of 20
00 polypropylene glycol (hereinafter abbreviated as PPG)
In the same manner as in Reference Example 1 except that 30 parts by weight and 7.2 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (hereinafter abbreviated as CYC epx) as a polyfunctional epoxy compound were used. A test piece and a flat plate were obtained.

< Reference Example 4 > Polyoxyalkylene glycol having an average molecular weight of 20
25 parts by weight of polytetramethylene glycol (hereinafter abbreviated as PTMG) of 00, ES as a polyfunctional epoxy compound
Test pieces and flat plates were obtained in the same manner as in Reference Example 1 except that 2.0 parts by weight of T epx was added.

< Reference Example 5 > Polyethylene naphthalate resin (NXP-1500, manufactured by Nippon Steel Tube, hereinafter referred to as PEN) as a thermoplastic polyester resin.
The test piece and the flat plate were obtained in the same manner as in Reference Example 1 except that it was omitted.

The ginseng except for using <Reference Example 6> PEN as the thermoplastic polyester resin, (hereinafter abbreviated as TGI EPx) triglycidyl isocyanurate as the polyfunctional epoxy compound 2.5 parts by weight
To obtain a test piece and flat plate in the same manner as considered Example 1.

Reference Example 7 PEN as a thermoplastic polyester resin, and trinonyl phenyl phosphite (hereinafter referred to as TNPP) as a phosphite triester compound instead of the polyfunctional epoxy compound.
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 except that 2.5 parts by weight was used.

[0034] <Reference Example 8> The polylactic acid resin as the thermoplastic polyester resin except for using (manufactured by Shimadzu Corporation, Lacty, hereinafter abbreviated as PLA) ginseng
To obtain a test piece and flat plate in the same manner as considered Example 1.

Example 2 As Reference Example 1 except that PLA was used as the thermoplastic polyester resin, and 1.2 parts by weight of 4,4′-diphenylmethane diisocyanate was used as the polyfunctional isocyanate compound instead of the polyfunctional epoxy compound. Similarly, a test piece and a flat plate were obtained.

Comparative Example 1 100 parts by weight of PET as a thermoplastic polyester resin, and PE as a polyoxyalkylene glycol were used.
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 except that G20 part by weight was added.

Comparative Example 2 100 parts by weight of PET as a thermoplastic polyester resin and PP as a polyoxyalkylene glycol were used.
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 by adding only G30 parts by weight.

Comparative Example 3 100 parts by weight of PET as a thermoplastic polyester resin and PT as a polyoxyalkylene glycol were used.
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 by adding only 25 parts by weight of MG.

Comparative Example 4 100 parts by weight of PEN as the thermoplastic polyester resin, PE as polyoxyalkylene glycol
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 except that G20 part by weight was added.

Comparative Example 5 100 parts by weight of PEN as a thermoplastic polyester resin, and PE as a polyoxyalkylene glycol were used.
A test piece and a flat plate were obtained in the same manner as in Reference Example 1 except that G20 part by weight was added. Table 1 shows the Izod impact values and surface resistivity values measured in the above Examples, Comparative Examples , and Reference Examples .

[0041]

[Table 1]

[0042]

According to the present invention, the thermoplastic polyester is excellent in antistatic property by blending a polyoxyalkylene glycol and a polyfunctional isocyanate compound, yet the impact resistance of the good molded article A thermoplastic polyester resin composition that can be produced is obtained.
Further, the thermoplastic polyester resin composition, similarly to general thermoplastic polyester resin, various moldings can be obtained by using molding methods such as injection molding, extrusion molding, stretch blow molding, and particularly containers and films. It is possible to provide a product which is preferably used as a packaging material for various uses such as.

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Claims (7)

(57) [Claims] Respect 1. A thermoplastic polyester having a polyoxyalkylene glycol, a reactivity with the thermoplastic polyester and polyoxyalkylene glycols,
A polyester resin composition comprising a reactive low molecular weight compound composed of a polyfunctional isocyanate compound . 2. A thermoplastic polyester comprising 100 parts by weight of polyoxyalkylene glycol in an amount of 1 to 50 parts by weight and a polyfunctional isocyanate compound in an amount of 0.01 to 25 parts by weight. The polyester resin composition as described in 1 . 3. The thermoplastic polyester according to claim 1 or 2, wherein the thermoplastic polyester is polyethylene terephthalate .
The polyester resin composition according to any one of claims . 4. A thermoplastic polyester characterized in that it is a polyethylene naphthalate claims 1 to 3 Noise
The polyester resin composition described therein. 5. The polyester resin composition according to claim 1, wherein the thermoplastic polyester is a biodegradable polyester composed of a polymer of oxyacid. 6. The polyester resin composition according to any one of claims 1 to 3, wherein the thermoplastic polyester is a biodegradable polyester composed of an oxyacid copolymer. . 7. A molded product obtained by molding the polyester resin composition according to any one of claims 1 to 6 .